The objective of the Morphology Core is to enhance the ability of the Center Investigators to perform digestive and liver research. The Morphology Core strives to provide high quality service and support to scientists with a commitment to teaching the techniques and providing the reagents necessary to perform morphologic analysis of gastrointestinal tract and liver tissues. This Core has grown substantially and has been extremely successful since July 1997, when it initiated services and provided reagents to Investigators of the Center for Molecular Studies in Digestive and Liver Disease. Dr. Silberg became the Director of the Morphology Core in 1998. The growth of the Core resulted in the hiring of Gary Swain, Ph.D. as the Technical Director. Drs. Silberg and Swain have been essential in expanding the scientific aspects of the Core by teaching techniques to Center Investigators and assisting in the development of protocols for new antibodies for immunohistochemistry. With the addition of two full time technicians, the Core has been able to provide quality services in a timely manner to the Center Investigators. The following description will outline the services provided by the Morphology Core. Morphologic data generated by some of the principle investigators will be presented as examples of the type and quality of work that can be expected. An important aspect of this core has been the collaboration and interactions that have occurred among its investigators. The Morphology Core is located on the 6th floor of the Clinical Research Building, in rooms adjacent to the scientific investigators in the Division of Gastroenterology, and easily accessible to all Center Investigators. Due to the close proximity of the Morphology Core to the user laboratories, it has become an important vehicle for Center Investigators, fellows, and technicians to collaborate and consult while performing immunohistochemistry or using the imaging equipment. Collaborations have been built through these interactions and we anticipate fostering future collaborations in this fashion. Importantly, the Molecular Biology Core is located across the hall from the Morphology Core, allowing for cohesive interactions in tissue procurement and analysis (e.g., Tissue bank, H&E sections and RNA extractions).